Petroleum reservoir

About: Petroleum reservoir is a research topic. Over the lifetime, 5403 publications have been published within this topic receiving 83535 citations. The topic is also known as: petroleum deposit.

Transient pressure analysis of horizontal wells in anisotropic naturally fractured reservoirs

Abstract: Analytical solutions are presented for pressure-drawdown and -buildup analyses of horizontal wells in anisotropic reservoirs with tectonic, regional, or contractional natural fractures. (The reservoirs might be limited by parallel sealed boundaries.) These solutions have led to the identification of various flow periods, including radial in a vertical plane, transitional as a result of flow from the matrix into the fractures, linear when the transient pressure reaches the upper and lower boundaries of the reservoir, pseudoradial toward the wellbore in horizontal plane, and linear when the transient reaches the outer parallel boundaries. Recognition of these flow periods leads to the calculation of p{sub i} or P*; permeabilities in the x, y, and z directions; storativity ratio, {omega}; average distance between natural fractures; fracture porosity; and fracture aperture, skin, and pseudoskin caused by vertical and horizontal partial penetration. In this paper calculations are illustrated with an example.

Stratification developing method for complex fault block thin oil reservoir

Abstract: The invention discloses a stratification developing method for a complex fault block thin oil reservoir. The method comprises the steps that the structure of the oil reservoir to be developed and the magnitude of edge-bottom water oil reservoir energy are determined; on the basis of determining the structure, fine geological stratification is achieved, and development units are detailed to single sand bodies; on the basis of fine geological stratification, the reservoir properties of all the single sand bodies are evaluated, and the spacing layer distribution conditions and physical characteristics of all the single sand bodies are determined; on the basis of determining reservoir evaluation, the residual oil distribution law and residual recoverable reserves of all the single sand bodies are determined through development effect analysis; after the residual oil distribution law is determined, series of strata recombination boundaries of horizontal well deployment target layers and vertical well drilling reservoir are obtained by utilizing numerical simulation in combination with field experience; on the basis of determining the conditions, according to the stratification developing technology, well pattern overall planning and deployment are carried out, and the stratification developing scheme is complied. According to the stratification developing method, the usage degree of the oil reservoir reserves can be increased, the development effect of the oil reservoir can be improved, and the recovery efficiency of the oil reservoir is enhanced.

Changing paradigms in oil and gas reservoir monitoring - the introduction and commercialization of in-well optical sensing systems

Abstract: Downhole measurements play a critical role in the production of oil and gas reservoirs. Parameters such as pressure, temperature and fluid flow provide valuable insights into the depletion dynamics of a reservoir that, if optimized, can be highly beneficial to the productivity and economics of the well. Unfortunately, oil and gas reservoirs represent some of the harshest, least accessible, environments on earth. This paper addresses the development and commercialization of fiber optic sensing systems to monitor the conditions of these reservoirs on a real time basis as the oil and gas is produced.

Influence of reservoir stress path on deformation and permeability of weakly cemented sandstone reservoirs

Abstract: The influence of production-induced changes in reservoir stress state on compressibility and permeability of weakly cemented sandstones has been analyzed. Laboratory experiments simulating reservoir depletion have been conducted for the full range of stress paths that a reservoir may follow. Samples were loaded by reducing the pore pressure and controlling the confining pressure according to the desired stress path from initial reservoir conditions. The results show that compressibility of weakly cemented sandstones are stress path dependent. Compressibilities measured under uniaxial strain conditions, or a stress path with a K value lower than the one associated with uniaxial strain, are more than twice the corresponding value found under hydrostatic loading conditions. In contrast, matrix permeability measured in the maximum stress direction show no significant stress path dependence. Independently of stress path, the observed permeability reductions fall within the general trend expected for a sedimentary rock of relatively high initial permeability. A significant permeability decrease was only observed as the shear stress exceeded the yield limit of the rock, probably due to both mobilization of fine arains and an increase in tortuosity due to collapse of pore space. Results of this study suggest that stress path dependent properties of weakly cemented sandstonesmore » is a consequence of the heterogeneous nature of the sedimentary rock. Material properties are affected by grain-scale inelastic deformation processes and the pattern of these deformation processes is primarily controlled by reservoir stress path.« less